This application has four aims: 1) To test whether the Internet is effective at reaching high-risk Internet-using Latino MSM (ILM); 2) to study Internet-mediated sexual liaisons as a risk for HIV; 3) to test a promising new HIV prevention intervention adapted for Internet use, and 4) to identify what features of the Internet constitute "best practices" when designing Internet HIV prevention. There are two study protocols proposed in this application. The first year will involve development of the instruments, adaptation of the Intervention for Internet use and pilot-testing of both surveys and interventions. In Protocol I ((Aims 1,2), we will recruit 964 ILM. A cross-sectional descriptive study is proposed to identify the sample. We will examine rate of HIV-related risk behaviors, and sexual and ethnic acculturation as a risk for HIV. Next, a retrospective study of last sexual encounters (Internet versus conventional) will use a within-subjects design where the subjects act as their own control to identify whether features of the Internet, person characteristics or a combination increase risk behavior in Internet-mediated sexual liaisons. In Protocol II, a randomized controlled trial utilizing three levels of experimental condition will follow subsample of 482 ILM across 18 months of follow-up to test whether on the Internet a sexual health approach to HIV prevention is more effective at reducing long-term risk behavior than conventional HIV programs. The levels of experimental condition will test whether adding bulletin boards and mediated chat room discussion groups significantly lowers risk long-term.